White dwarfs get dimmer and dimmer until they eventually stop burning and go dark, thus becoming black dwarf stars — the theoretical final stage of a star's evolution. Scientists study white dwarfs like Sirius B in hopes of gaining a better understanding of the stellar cycle. Eventually, Earth's sun will cycle to the white dwarf stage as well. The mass of a star is an important factor in the object's stellar evolution, because it determines the star's core temperature and how long and hot the star will burn.
Astronomers can calculate the mass of a star based on its brightness, or luminosity, but this was challenging for Sirius B. The luminosity of Sirius A overpowered ground-based observations, making it impossible to isolate the much dimmer luminosity coming from Sirius B.
It wasn't until , when a team of astronomers assembled data collected by the Hubble Space Telescope, that scientists were able to measure the mass of Sirius B for the first time.
They found that the star has a mass that is 98 percent that of Earth's sun. Because Sirius is a young star, it's not likely to have planets orbiting it. Nonetheless, the data TESS collects can be used to study variabilities in star brightness and the appearance of supernovas. Join our Space Forums to keep talking space on the latest missions, night sky and more!
And if you have a news tip, correction or comment, let us know at: community space. Elizabeth Howell is a contributing writer for Space. She is the author or co-author of several books on space exploration. Bacon STScI. Sirius or Sirius A is a main-sequence star of spectral type early A. Sirius B is one of the largest known white dwarf stars and is 10, times dimmer than Sirius. It is calculated on brightness and luminosity.
This has made measuring the luminosity of Sirius B quite a challenge, as the luminosity of Sirius A overpowers ground-based observations. For those in the northern hemisphere, Sirius is lower in the sky where there is a thicker atmosphere. In Greek mythology, Canis Major has been known to represent the bigger dog following Orion and is often depicted pursuing a hare, represented by the constellation Lepus shown below.
Sirius is located in Canis Major, a dog next to Orion. Related Articles Astronomy Stars. Tags sirius constellations.
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